utils-std

sendfile_linux.c (748B)

// utils-std: Collection of commonly available Unix tools
// SPDX-FileCopyrightText: 2017 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
// SPDX-License-Identifier: MPL-2.0
#define _DEFAULT_SOURCE
#include "./fs.h"
// for sendfile
#include <sys/sendfile.h>
// generic
#include <errno.h>
#include <stddef.h>    // NULL
#include <sys/types.h> // ssize_t, off_t
ssize_t
auto_fd_copy(int fd_in, int fd_out, size_t len)
{
	off_t *off = NULL;
	while(1)
	{
		ssize_t ret = sendfile(fd_out, fd_in, off, len);
		if(ret < 0)
		{
			switch(errno)
			{
			case EINVAL:
				errno = 0;
				return manual_copy(fd_in, fd_out, len, 0);
			case EAGAIN:
				errno = 0;
				continue;
			default:
				return ret;
			}
		}
		return ret;
	}
	return -1;
}